#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>




int main()
{
	int a = 0;
	int b = 0;
	int c = 0;
	while (scanf("%d %d %d", &a, &b, &c) == 3)
	{
		if (a + b > c && a + c > b && b + c > a)
		{
			if (a = b = c)
				printf("Equilateral triangle");
			else if (a == b || a == c || b == c)
			{
				printf("Isosceles triangle");
			}
			else
				printf("Ordinary triangle");
		}
		else
			printf("Not a triangle");
	}
	return 0;
}